Abstract
For endodontic treatments requiring precise technique, extensive experience is essential for the practitioner to make use of scientific evidence in the treatment. However, scientific evidence is not necessarily abundant in endodontics, although there are not a few instances of evidence derived from experience. Practitioners have established highly reliable evidence through their accumulation of experience, which are supported by the clinical results.
An examination of prognoses of periapical lesions 10 years after treatment revealed that 70% of cases (78% excluding tooth extraction) were judged to be cured. Most of the cases showing inferior prognosis were of retreatment for the reasons of deficient root canal preparation due to abnormal shape of the root canal and leftover root canal filling material. Examples of extracted teeth without periapical lesions totaled 9%.
Subsequently, the method of treatment was improved on the basis of these results. Endodontic treatment should be based on the following procedures: ① giving top priority to conservation of tooth structure, ② removing antigens, ③ blockage of the root canal and ④ presuming retreatment. It was also reconfirmed that the removal of antigen materials should be considered significantly important in endodontic therapy.
It is necessary to follow up on long-term prognoses to increase the success rate of endodontic treatment. As there is insufficient consensus about many concepts of endodontic treatment between basic researchers and practitioners, it is desirable that both groups cooperate in their efforts to find scientific evidence.
